Gathered end hammock
15 degree Big Agnes down bag with 15 degree inflatable pad
1/4 EVA foam pad with shoulder wings and full head to foot coverage
I am currently unemployed, so I have had a lot of time to experiment with my winter set-up. I was mostly warm with the above setup [hanging on my rear screened porch in temps down to the high teens]. But, I still had a COLD butt... I guess that my weight pressed enough air out of the BA inflatable pad to make that area thin enough to get colder than the rest of me.
Soooo, I had found a rectangluar air pillow in a thrift shop similar to the BA pillow, so I thought it might come in handy for something. http://www.trailspace.com/gear/big-a...r-core-pillow/
Well, it was pretty nice as a pillow, but I decided just to nearly deflate it and slide it under my rear end. After a couple of minutes, it felt like being on a heating pad.
So, there you have it. Works for me, YMMV.